This project converts the primer2 into a gps handheld device. A gps receiver module on the extension board is sending its data to the primer2 which is showing your actual position on a map. This map is read from the micro-sd card of the primer2 and has been previously downloaded from the OpenStreetMap project.

Connecting a gps receiver to a microcontroller is not a big deal. Most commonly the gps receiver sends its data, packed into NMEA format, as a serial stream over a serial port. But what to do with this data? For tracking purposes its just enough to save the datastream to a nonvolatile memory. But if you want to visualize the gps data on your device, for example show your actual position on a map you are facing two problems:

So all you have to do is download the desired map data from OSM project and save it to the micro-sd card. OSM4Primer2 extracts the actual geografical position out of the NMEA datastream and correlates it to map data on the micro-sd card. As a result the position is shown on the map.

The project as a hole consists of three parts:

a primer2 extension board with a gps receiver module with antenna. This module sends position data over a serial data stream to the usart2 of the primer2. This data stream is packed into the NMEA data format.

a CircleOS application, that extracts position data from the data stream and loads the appropriate map from sd-card. Actual position is shown on the map.

A pc host applications that downloads the desired maps from the OpenStreetMap project, and convert the original OpenStreetMap parts of the worldmap (so called „tiles“) into primer2 *.prm files that can be directly displayed on primer2 lcd